Scientific analysis of paintings contributes to the prolongation of life expectancy of major art works through better understanding of the phenomena of change. Information gained through the use of visible light (natural light, raking, monochromatic sodium), UV, IR and x-ray is detailed. Information furnished by microscopy, chromatography and spectrography carried out at the Research Laboratories of the Museums of France is also listed. Dating methods still in the experimental stage are also given. The scientific analysis also includes study of the influence of the climate, pollution, vibration and lighting. L.W. -- AATA